eyes and visual pathway

Question 1

what are the 5 structures of the external eye

Answer 1

• lacrimal caruncle
• semilunar fold
• sclera
• pupil
• iris

Question 2

what 3 structures are part of the palpebral tissue ( area between open eyelids)

Answer 2

• iris
• sclera
• pupil

Question 3

what is the role of eyelahses

Answer 3

• stop particles getting into eye and scratching cornea
• contain lipid-rich secretion to stop eyelids sticking together, we blink to spread tears over the surface of eye to keep it

Question 4

why do we have the semilunar fold (when its useless)

Answer 4

evolutional remnant from when we has secondary eyelids like lizards

Question 5

what are the 6 internal structures of the eye (not including iris and pupil)

Answer 5

• tarsal plate (inner side of eyelid)
• lens
• cillary body
• retina
• choroid
• sclera

Question 6

the sclera, choroid and sclera are 3 layers of the body of the eyeball, what are the functions of these

Answer 6

sclera - white of eye, fibrous tunic

choroid - vascular

retina - pigmented to capture light info

Question 7

explain how we see images/ how our eyeball depicts images

Answer 7

• light travels in straight line
• lens is required to bend the light so it can focus on the retina
• this explains why image is upside down, due to depth of eyeball
• info detected by retina and sent along optic nerve

Question 8

describe how the rays of light differ coming from a distant or nearby object

Answer 8

• nearly parallel rays coming from DISTANT object
• divergent rays coming from CLOSE object

Question 9

what are the 7 bones that make up the orbits

Answer 9

• frontal
• zygomatic
• lacriminal
• sphenoid
• ethmoid
• palatine
• maxilla

Question 10

what are the 3 apertures/ foramen found in the orbits

Answer 10

superior/infeiror orbital fissure
optic canal

Question 11

find diagram and label all bones of orbits

Question 12

what is the lacrimal apparatus

Answer 12

structures that secrete tears and drain them from the surface of the eyeball

Question 13

what is the lacrimal gland and where is it found

Answer 13

• almond sized and found in the upper outer margin of each orbit
• primary function of secreting the aqueous portion of the tear

(aprox a dozen small darts lead from each gland and drain into conjunctivae)

Question 14

what is the lacrimal canal

Answer 14

small channels that empty into lacrimal sacs

Question 15

what is the lacrimal sac

Answer 15

located in a groove in lacrimal bone

• collect tears that drain out of your eyes through your lacrimal puncta

Question 16

what is the lacrimal puncta

Answer 16

the openings that pump tears out of your eyes/ or drain them

Question 17

what is the nasolacrimal ducts

Answer 17

• small tubes that extend from the lacrimal sac into the inferior meatus of nose

(thats why nose runs when u cry)

Question 18

find image of lacrimal apparatus and label each structure

Question 19

what are the 6 muscles of the eye

Answer 19

• lateral and medial rectus
• inferior and superior rectus
• inferior oblique and superior oblique rectus

Question 20

what movement does the lateral and medial rectus muscle allow fro

Answer 20

outward and inward movement (left and right)

Question 21

what movement does the inferior and superior rectus muscle allow for

Answer 21

up and down

Question 22

what movement does the inferior/superior oblique rectus muscle allow for

Answer 22

inferior oblique = upwards and outwards

superior oblique = downwards and outwards

Question 23

what are the 3 ligaments of the eye

Answer 23

• medial and lateral check lig
• suspensory lig

Question 24

what maintains the vertical position of the eyeball

Answer 24

suspensory ligament

Question 25

what maintains the anteroom-posterior position of the eyeball

Answer 25

lateral/medial check ligament, fascial sheath and orbital fat

Question 26

what is the main muscle located in the eyelid and what is its function

Answer 26

- levator palpebrae superioris - controls elevation and retraction of eyelids

Question 27

find and label orbital and nearby structures on CT/MRI scan

Question 28

what 2 arteries supply the orbit

Answer 28

- ophthalmic artery - internal carotid artery

Question 29

define visual field

Answer 29

The visual field refers to the total area in which objects can be seen in the side (peripheral) vision as you focus your eyes on a central point.

Question 30

what 2 halves can the retina be split into

Answer 30

temporal and nasal retina

Question 31

which sides of the retina are responsible for the left or right visual field

Answer 31

nasal retina = left visual field temporal retina = right visual field

Question 32

what is the optic chasm

Answer 32

the part of the brain where the optic nerves cross

Question 33

what is the sella turcica

Answer 33

a depression in the sphenoid bone, containing the pituitary gland

Question 34

how does the optic chasm and sella turcica sit relative to each other

Answer 34

the optic chiasm is sat above the sella turcica

Question 35

why is vision affected if there is a pituitary tumour

Answer 35

the growth of the pituitary tumour within the sella turcica will press against the optic chiasm

Question 36

what is acromegaly

Answer 36

abnormal growth of the hands, feet, and face, caused by overproduction of growth hormone by the pituitary gland.

Question 37

what are the optic radiations

Answer 37

- a projection tract that connects the lateral geniculate nucleus to the primary visual cortex in the occipital lobe. - It functions to transmit visual input coming from the retina, the optic nerve, and the optic tract.

Question 38

which lobe of the brain o the inferior optic radiations pass through

Answer 38

temporal

Question 39

which lobe of the brain do the superior optic radiations pass through

Answer 39

parietal

Question 40

how can lesions in the parietal or temporal lobe lead to affected sight

Answer 40

- they will interrupt the inferior or superior optic radiations, iand affect the transmission of visual input from the retina

Question 41

in which lobe is visual information processed

Answer 41

occipital

Question 42

where/how pathway = posterior parietal cortex what pathway = inferior temporal cortex

Question 43

what artery supplies the occipital lobe

Answer 43

posterior cerebral artery

Question 44

look through axial stack of visual pathway, screenshotted